Mitogen-activated protein kinases (MAP) is a family of proline-directed serine/threonine kinases that activate their substrates by dual phosphorylation. The kinases are activated by a variety of signals including nutritional and osmotic stress, UV light, growth factors, endotoxin and inflammatory cytokines. The p38 MAP kinase group is a MAP family of various isoforms, including p38α, p38β and p38γ, and is responsible for phosphorylating and activating transcription factors (e.g. ATF2, CHOP and MEF2C) as well as other kinases (e.g. MAPKAP-2 and MAPKAP-3). The p38 isoforms are activated by bacterial lipopolysaccharide, physical and chemical stress and by pro-inflammatory cytokines, including tumor necrosis factor (TNF-α) and interleukin-1 (IL-1). The products of the p38 phosphorylation mediate the production of inflammatory cytokines, including TNF and IL-1, and cyclooxygenase-2.
TNF-α is a cytokine produced primarily by activated monocytes and macrophages. Excessive or unregulated TNF production has been implicated in mediating a number of diseases. Recent studies indicate that TNF has a causative role in the pathogenesis of rheumatoid arthritis. Additional studies demonstrate that inhibition of TNF has broad application in the treatment of inflammation, inflammatory bowel disease, multiple sclerosis and asthma.
TNF has also been implicated in viral infections, such as HIV, influenza virus, and herpes virus including herpes simplex virus type-1 (HSV-1), herpes simplex virus type-2 (HSV-2), cytomegalovirus (CMV), varicella-zoster virus (VZV), Epstein-Barr virus, human herpesvirus-6 (HHV-6), human herpesvirus-7 (HHV-7), human herpesvirus-8 (HHV-8), pseudorabies and rhinotracheitis, among others.
IL-8 is another pro-inflammatory cytokine, which is produced by mononuclear cells, fibroblasts, endothelial cells, and keratinocytes, and is associated with conditions including inflammation.
IL-1 is produced by activated monocytes and macrophages and is involved in the inflammatory response. IL-1 plays a role in many pathophysiological responses including rheumatoid arthritis, fever and reduction of bone resorption.
TNF, IL-1 and IL-8 affect a wide variety of cells and tissues and are important inflammatory mediators of a wide variety of disease states and conditions. The inhibition of these cytokines by inhibition of the p38 kinase is of benefit in controlling, reducing and alleviating many of these disease states.
Various pyrazoles have previously been described. U.S. Pat. No. 4,000,281, to Beiler and Binon, describes 4,5-aryl/heteroaryl substituted pyrazoles with antiviral activity against both RNA and DNA viruses such as myxoviruses, adenoviruses, rhinoviruses, and various viruses of the herpes group. WO 92/19615, published Nov. 12, 1992, describes pyrazoles as novel fungicides. U.S. Pat. No. 3,984,431, to Cueremy and Renault, describes derivatives of pyrazole-5-acetic acid as having anti-inflammatory activity. Specifically, [1-isobutyl-3,4-diphenyl-1H-pyrazol-5-yl]acetic acid is described. U.S. Pat. No. 3,245,093 to Hinsgen et al, describes a process for preparing pyrazoles. WO 83/00330, published Feb. 3, 1983, describes a new process for the preparation of diphenyl-3,4-methyl-5-pyrazole derivatives. WO 95/06036, published Mar. 2, 1995, describes a process for preparing pyrazole derivatives. U.S. Pat. No. 5,589,439, to T. Goto, et al., describes tetrazole derivatives and their use as herbicides. EP 515,041 describes pyrimidyl substituted pyrazole derivatives as novel agricultural fungicides. Japanese Patent 4,145,081 describes pyrazolecarboxylic acid derivatives as herbicides. Japanese Patent 5,345,772 describes novel pyrazole derivatives as inhibiting acetylcholinesterase.
Pyrazoles have been described for use in the treatment of inflammation. Japanese Patent 5,017,470 describes synthesis of pyrazole derivatives as anti-inflammatory, anti-rheumatic, anti-bacterial and anti-viral drugs. EP 115640, published Dec. 30, 1983, describes 4-imidazolyl-pyrazole derivatives as inhibitors of thromboxane synthesis. 3-(4-Isopropyl-1-methylcyclohex-1-yl)-4-(imidazol-1-yl)-1H-pyrazole is specifically described. WO 97/01551, published Jan. 16, 1997, describes pyrazole compounds as adenosine antagonists. 4-(3-Oxo-2,3-dihydropyridazin-6-yl)-3-phenylpyrazole is specifically described. U.S. Pat. No. 5,134,142, to Matsuo et al. describes 1,5-diaryl pyrazoles as having anti-inflammatory activity.
U.S. Pat. No. 5,559,137 to Adams et al, describes novel pyrazoles (1,3,4-substituted) as inhibitors of cytokines used in the treatment of cytokine diseases. Specifically, 3-(4-fluorophenyl)-1-(4-methylsulfinylphenyl)-4-(4-pyridyl)-5H-pyrazole is described. WO 96/03385, published Feb. 8, 1996, describes 3,4-substituted pyrazoles, as having anti-inflammatory activity. Specifically, 3-methylsulfonylphenyl-4-aryl-pyrazoles and 3-aminosulfonylphenyl-4-aryl-pyrazoles are described.
Laszlo et al., Bioorg. Med. Chem. Letters, 8 (1998) 2689-2694, describes certain furans, pyrroles and pyrazolones, particularly 3-pyridyl-2,5-diaryl-pyrroles, as inhibitors of p38 kinase.
The invention's pyrazolyl compounds are found to show usefulness as p38 kinase inhibitors.